The present invention relates to a process for manufacturing reformed coal.
Techniques for manufacturing coal have heretofore been described in the literature, for example, U.S. Pat. No. 3,341,447 in which coal mixed with coal oil as a solvent is heated under pressure with hydrogen, whereupon the organic substance in coal is depolymerized and solved in the coal oil, the minerals and unreacted coal residues contained in a liquidfied solvent are separated by a mechanical method, such as filtration, and a solvent refomed coal is produced. However, according to the technique described above, a large supply of coal oil is necessary. If all of this oil is supplied from the oil produced in this system, the coal must be subjected to severe conditions with the result that more organic substance is depolymerized. Unfortunately, in this case the productivity of reformed coal becomes lower. If coal oil is supplied from the outside, coal tar is best. But the quantity required and its price represent serious problems regarding the feasibility of the process. Moreover, the foregoing demands a large amount of hydrogen, and a supply thereof is another very important problem technically and economically.
On the other hand, it has also been proposed to use as the solvent the aromatic-rich substance which is made from heat treatment of petroleum oil, and in this case hydrogen is not used. (Joural of Japan Petroleum Institute, Vol.117, No.10 (1974). But, according to this technique another serious problem remains, namely, any organic sulphur and other impurities in coal and/or the solvent are brought into the product because no hydrogenation step is used.
In addition, it has hitherto been an obvious fact that coal oil which is rich in aromatic substance and petroleum oil which is rich in aliphatic substance are not thought of as being compatible with each other.